The subject matter herein relates generally to connector systems having mating connectors, and more particularly, to connector systems that include shielding to restrict emission of electromagnetic interference (EMI).
Known connector systems include connectors that each have contacts that engage each other to communicate data signals between the contacts. Some connector systems include connectors with pairs of contacts that communicate high speed differential signals. The connectors may include conductive shields that attempt to restrict emission of EMI from the contacts outside of the connectors. For example, each of the connectors in a connector system may include shields that enclose the contacts of the connector. The shields may be electrically joined with a ground reference to transfer the energy of at least some of the EMI to the ground reference. By transferring at least some of the EMI to the ground reference, the shields prevent at least some of the EMI from radiating to other nearby connectors. The EMI that does radiate to nearby mated contacts may induce noise in the signals that are communicated by the mated contacts and thereby degrade the signal to noise ratio of the mated contacts.
Some known shields include elongated protrusions or tongues that engage the shield of another connector. For example, a first connector may have a shield with a protrusion that is received in the shield of a second connector to electrically couple the two shields with each other. The protrusion may extend to an outer end that engages the shield of the other connector in order to electrically couple the shields. But, the protrusion may only contact the shield of the other connector at the outer end of the protrusion. This may leave an overhanging portion of the shield between the point of contact with the protrusion and the front end of the shield to act as an antenna. As a result, EMI energy received by the overhanging portion of the shield from the contacts in the connectors may oscillate along the length of the overhanging portion. For example, the energy of the EMI may oscillate between the point of contact of the protrusion with the shield and the front end of the shield along the overhang portion of the shield. The oscillation of the EMI energy may cause the shield to behave as an antenna. For example, the shield may radiate the EMI similar to an antenna radiating a wireless data signal. The radiated EMI can interfere with data signals being communicated using other nearby connectors.
Some other known shields have sidewalls that extend from the shield to exposed edges. The exposed edges may not be coupled or joined with any other conductive body or shield. As a result, EMI energy that is transferred to the sidewalls may oscillate along the sidewalls between the exposed edges and the remainder of the shield. As described above, the oscillating EMI energy may cause the sidewalls to radiate the EMI similar to an antenna.
Thus, a need exists for a connector system that restricts the radiation of EMI from the shields of the connector system.